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Starizona SCT Corrector IV f/6.3 reducer/coma corrector

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I recently acquired a Starizona f/6.3 corrector for my C6 and have now processed my first pic with it, M37. I'd have to say I'm very pleased with the improvement over the old Celestron f/6.3 reducer I was using previously. (The slightly stretched stars in the top right are due to a slight mis-collimation - now sorted!)

I've attached the corner of a typical image taken with the old Celestron reducer - you can see just how bad the coma was. No to mention the weird internal reflections I used to get from bright stars.

When I first saw the preview image with the Starizona corrector on my laptop screen I'll admit to letting out a "WOW"! It positively leaped off the screen at me.

Further advantages are that the star colours are much better saturated, without the massive amount of CA around them that I was seeing with the Celestron reducer, and they have a nice "glow" to them.

One slight negative is that it slots into a 2 inch visual back. I'd much prefer if it screwed in place given the, ahem, somewhat expensive equipment hanging off the back of it, but I understand this gives some flexibility with back focus.

The corrector produces a focal length of 1225mm, so ideal for smaller object like galaxies - and just in time too! In fact, I'm currently putting it to good use on M88 👍 If anyone else is currently struggling with the Celestron reducer and looking for something better then I'd wholeheartedly recommend the Starizona. It's pricey (I ordered direct from Starizona themselves) but a flat field in a compact 6-inch scope is definitely worth it.

I'm really looking forward to imaging with this over the coming months and years.




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I've seriously thought of getting one of these for my 8 inch SCT... My Celestron version isn't too bad, far from perfect but not unacceptable

The few things stopping me are no solid screw on fittings, it would give me a focal length of 1400 odd instead of the 1280 from the Celestron version, and I know of a guy with a 9.25 which has one, has issues and has zero support from starizona.. they don't even reply to his multiple emails... 

Is the lower pic from the Celestron version?

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Oh dear that's not too good about the lack of support from Starizona. I've not had to speak with them myself so couldn't comment on that personally. Aftersales support is so important though so I can fully understand any hesitation that may cause.

But yes, the lower pic is from the old Celestron reducer. I think your summary of the Celestron reducer as "far from perfect but not unacceptable" is accurate - I simply cropped into the image to remove most of the coma around the edges. I took some pretty good images with it (at least, by my standards 😄), one of which is up on my wall and you'd need to point out the bad stars to a casual observer. There was always plenty of tidying up of the stars required in post-processing though.

It really is night and day between the Celestron and Starizona reducers - I'm certainly glad I have it. I'll try to get some pics up of it. It also has some of the nicest coatings I've ever seen - a real rainbow of colour down into the lenses. A minor thing but, hey 🙂

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On 09/05/2023 at 08:31, RobertI said:

Presumably the resulting focal length on your C6 is around 950mm?

Focal length is 1225mm with the Starizona (it was around 1025mm with the Celestron reducer). They mention that the reducer is a 0.63x reduction but that the C6 (and C8) are closer to f/11 than f/10, although if that were the case it would put the native FL of my C6 at around 1944mm which is very unlikely. Supposing the scope is indeed f/11 then the reducer is giving a reduction of 0.74x.

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I have one as well for many years (I think not long time after they released it) on my C8 (after testing 3 Celestron....). No comparison, way better than original celestron and I would put B_Unk_078_012333_009_mosaic.jpg.92f1b42c702335725c1a7653190395e2.jpgit among all my best buy of astro stuff.

below a quick b color with SX694 camera. 


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